When a plurality of five to ten sows are in a pasture with their pigs problems arise when the sows farrow in that several sows will attempt to farrow in two or three hog houses with the result that the hog houses are crowded and some of the pigs are forced into hog houses without sows. These pigs can become chilled without the body heat of a sow in the hog house. Further, pigs, during the time from farrowing to weaning time, often become injured as a result of movement of a heavy sow within a hog house into the areas of the hog house occupied by several pigs.
Although various types of structures have been heretofore designed to accommodate sows and to prevent sows from crushing pigs when farrowing these previously designed structures have, for the most part, proven ineffective in certain areas of operation.
Examples of previously patented structures of these types may be found in U.S. Pat. Nos. 2,602,419, 2,993,471, 2,966,883, 3,106,188 and 3,237,600.